Updating a hardware-specific display driver (i.e., a display driver that may be used to control video graphics display associated with a piece of hardware) has always required rebooting. Such a hardware-specific display driver may be referred to as an independent hardware vendor (IHV) display driver.
In previous operating systems, it was not possible to update the display driver without requiring a reboot. The graphics architecture in these operating systems did not support the fact that a display driver would be completely “stopped” from running and then dynamically updated to a completely new display driver. For example, driver resources typically need to be released in order to change to a new driver. In previously-available operating systems, there was no way to release resources. Consequently, the user had to shutdown to release the resources. For the kernel side of the operating system to recognize the presence of a new driver, the user would have to reboot. Also, a driver is typically used by a number of clients. In previously-available operating systems, there was no way to stop clients from using the driver. Accordingly, if the clients could not be stopped from using the driver, then the driver could not be changed. Rebooting the system would force all clients to stop using (i.e., disconnect from) the driver.
It would be desirable, however, if a display driver could be updated without requiring a reboot, while maintaining certain functionality, such as 2D for example, and state of the operating system.